Stranger for unfinished ruler? (9)
I believe the answer is:
foreigner
'stranger' is the definition.
(I know that foreigner is a type of stranger)
'for unfinished ruler?' is the wordplay.
'unfinished' means to remove the last letter.
'ruler?' becomes 'reigner' (someone who reigns).
'for' with its last letter taken away is 'fo'.
'fo'+'reigner'='FOREIGNER'
(Other definitions for foreigner that I've seen before include "Stranger, outsider" , "chauvinist holds in contempt" , "Alien" , "One from abroad" , "asylum seeker?" .)